I think one bad Linux habit is using it and not taking the time to learn anything new. You can get so set in your usual workflow every day, but you really should spend at least a little time each week tinkering with something, reading about a program everyone is talking about, or refreshing your memory about those flags on that command that you always forget.
rm -rf does not give you a dialogue, because you used -f to ask it not to give any dialogue. rm -r asks about every file, which can be annoying. Just get into the habbit of at least using ls with the same expression/globbing as your rm command.
